Adult brain function and behavior are influenced by neuronal network formation during development. Consequently, disturbances of brain development may underlie the pathology of adult mental disorders, such as schizophrenia (SZ) and mood disorders. Consistent with this notion, genetic susceptibility factors for these disorders that have been recently indentified, including Disrupted-in-Schizophrenia-1 (DISC1) and PCM1, have roles during neurodevelopment and are likely to cooperate, forming molecular pathways. Meanwhile, epidemiological studies have indicated that many environmental factors contribute to schizophrenia during neurodevelopment. P50 Schizophrenia Research Center at Johns Hopkins, therefore, is to address the key question of how defects of cortical development elicited by combinations of genetic and environmental risk factors lead to molecular, histological, and behavioral deficits associated with the frontal cortex in adulthood, which are relevant to SZ. Based on our preliminary studies, we hypothesize that DISC1 and its interactors are useful genetic probes for this study. Accordingly, the four major aims of this entire center are as follows: 1) to clarify the mechanisms whereby several different combinations of DISC1 and interactors (e.g., Karilin-7, PCM1, RPGRIP1L, CRMP2, nNOS, and NDEL1) mediate distinct processes during neurodevelopment, which in turn affect postnatal brain maturation and result in deficits of the frontal cortex and behavioral abnormalities relevant to SZ; 2) to determine how environmental factors relevant to SZ (prenatal immune activation, postnatal activation of complement cascade, and postnatal infection of Toxoplasma Gondii) influence genetic vulnerability associated with DISCI, which eventually contribute to the deficits of the frontal cortex and behavioral abnormalities relevant to SZ; 3) to identify molecular targets for possible biomarkers of SZ and SZ-associated endophenotypes by comparing altered expression profiles in preclinical models and human tissues; 4) to identify rare genetic variants associated with SZ and/or some endophenotypes associated with SZ by pinpointing novel candidates for genetic sequencing from biological studies. In this center, 6 projects and 2 cores will collaborate to achieve these scientific goals.